Closure of a medicament well

ABSTRACT

A closure for a medicament well (1) with a central closing luer-shaped body (2) and, if desired, a round body (2), and a luer-lock skirt extending substantially in parallel with the latter, comprises a void (4), which is provided in the upper end of closure (2) and defined against the outside by a flexible wall (5) on the upper side and on the other side is made to communicate with the outside, via a channel (6) extending through body (2).

BACKGROUND OF THE INVENTION

The present invention relates to a closure for a medicament well.

More preclcely, the invention relates to a closure for a medicament wellon a cannula, wlth a central, closing body and, If deslred, a round bodyand a sklrt extending substantially in parallel with the latter.

There is mainly one kind of intravenous cannulae on the market atpresent, vlz. a kind where a clrcular medicament well projectingnormally to the liquid channel in the lntravenous cannula is closed fromabove by the ald of a conventional cap, whlch is commonly fastened tothe sleeve of the medicament well by the ald of a more or less sturdyfastening strap.

The present cannulae with a medicament well of a conventional kind showthe inherent deficiency that after administration of medicament andremoval of the administrating syringe, there is always a small volume ofmedicament solutlon left in the well due to the counterpressure from theliquid flowing in the cannula.

This phenomenon may represent quite a health hazard, since the volume ofmedicament remaining in the medicament well may act as a substrate forbacteria, or the medicament may be subjected to decomposition ormetamorphosis due to influence from the outside environment.

This is probably one of the reasons for the fact that this kind ofintravenous cannula ls not accepted by the FDA on the American market.

Body heat may also cause undesirable changes.

Often, hours may pass between each time the medicament well is used, andthis enhances the hazard of undesirable changes.

When the medicament well is used again, the medicament phase which maybe modified or decomposed will be pushed into the cannula and introducedinto the body, which may cause undesirable and even dangerous states.

Another aspect that should be considered in this connection is that whensmall volumes of medicaments are administered it may occur that not allof the medicsmerit is injected, since some of it is left in the well.

SUMMARY OF THE INVENTION

It is an object of the present invention to remedy the shortcomings ofknown technology and to provide a device which permits completedischarge of the well. In this manner, any hazard of administratingcontaminated material to the patient is avoided, decomposition ormodification of a medicament remaining in the well is avoided, andcomplete administration of the medicament to the patient is ensured.

This is achieved by the aid of a closure of the above mentioned kind,and this closure is characterized by a void provided in the upper end ofthe closure, which is defined against the outside on top by a flexiblewall and is on the other side made to communicate with the outside, vias channel extending through the closure body.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is disclosed in more detail with reference to theaccompanying drawings, in which:

FIG. 1 shows a medicament well with an inserted syringe foradministration of a medicament;

FIG. 2 shows a conventional closure;

FIG. 3 shows a closure according to the invention in the same phase asthe conventional closure according to FIG. 2; and

FIG. 4 shows a closure according to the invention immediately after theremaining resldue was squeezed out of the well.

DETAILED DESCRIPTION

In FIG. 1, the luer 8 of a syringe 7 is inserted into the medicamentwell 9 1 of a cannula, for administration of medicament solutlon 10.

When medicanent solution 10 is injected into the liquid path 12 insidethe cannula, a flexible tubular valve 11 is urged to temporarily open,as indicated in FIG. 4. Upon completed injection the counter-pressure inliquid 12 urges valve 11 back into contact with the cannula sidewall,including about the perimeter of the juncture 15 of the well with thecannular sidewall, thereby closing of the well from the liquid pathinside the cannular, at that juncture. Upon removal of syringe 10 andinsertion of a closure the situation is as shown in FIG. 2 and 3, with aconventional closure, 2, 3, 13 and a closure 2, 3, 4, 5, 6, 13,according to the invention, respectively.

A residue of medicament solution 10 will remain on the bottom of well 1,in both the conventional device (FIGS. 1 and 2) and the device accordingto the present invention (FIGS. 1 and 3). This residue may, as mentionedabove, be subjected to decomposition of metamorphosis, and/or it mayrepresent great values of economlc and therapeutic kinds.

Use of the closure, according to the invention, permits utilization ofthe residue 10 as well by removing the residue 10 from the well 1 andurging it into the liquid path 12.

This is achieved by the aid of the arrangement according to theinvention by the fact that the flexible wall 5 which defines anair-filled vold 4 uppermost in the closure is compressed, as shown InFIG. 4. Consequently, air is discharged from within the enclosed void 4through the channel 6 In the central body 2 of the closure, into thelocation of the residual liquid 10 and urges residual liquid 10 past thevalve 11 and into the liquid path 12.

Upon compression the domed flexible wall 5 which overlies the void 4,towards the dished depression or seat 14 which underlies the void 4,such as to materially diminish the volume of the of void 4 and resultantdisplacement of the residual liquid 10 through the juncture 15, and pastthe valve 11 into the liquid path 12 within the cannula 9, thecounterpressure in the liquid 12 causes the valve 11 to again contactthe cannula wall 1 perimetrically of the juncture 15 andcircumferentially of the sidewall of the cannula 9, thereby againclosing off the well 1 from the liquid path 12.

The channel 6 formed within the externally tapered central body or plug2 of the closure extends axially between the center of the dished seat14 and the axially inner end 16 of the body 2, in the portion of thespace enclosed by the well 1, axially between the body 2 and thejuncture 15, where the residue 10 is located during the FIG. 3 state.

The invention is preferably used for closures of respective cannulaewells which are fastened to the cannula, e.g. each by the aid of arespective strap 13. However, there is nothing to prevent the closureaccording to the invention from being separate and used on various kindsof multi-way valves and cocks, as commonly used within this field ofmedical technology, so as to solve the same problems as regards residuesof medicaments.

According to an especially preferred feature of the invention, thedifference in volume of the void 4 between the expanded (FIG. 3) andcompressed (FIG. 4) states thereof is substantially equal to the volumeof the residue of medicament solution 10 remaining at the bottom of well1 in the FIG. 3 state for complete removal of the residue without airbeing introduced into the liquid flow 12.

It is, thus, possible to remove remaining medicament solution from wellsor corresponding injection sleeves in a simple and hygienic manner inorder to avoid the above-indicated problems in a simple and safe manner.

I claim:
 1. A closure for closing, and flushing liquid residue from anoutwardly opening, peripherally walled medicament well which at a basethereof has a juncture through an opening normally closed by abackflow-preventing check-valve, with a liquid path extending generallyat a right angle to the well, centrally of the tubular sidewall ofcannula,said closure comprising: a plug having an axially inner end, andaxially outer end and a sidewall sized to permit the plug to betelescoped into the well to a given axial extent limited by engagementof a feature on the plug with a feature on the cannula, at which theplug sealingly closes the well distally of the base of the well andleaves a medicament residue-accommodating chamber having a first givenvolume within the well between the axially inner end of the plug and thejuncture of the base of the well; the outer end of said plug includingan outwardly dished depression covered by a flexible dome wall which ina first state thereof is outwardly bulged and which is perimetricallyjoined to said plug so as to overlay said dished depression and formtherewith in said first state thereof an enclosed, normally air-filledvoid having a second given volume, and which flexible dome wall in asecond state thereof is internally convex towards said depression andthereby substantially diminish said void volumetrically to a third givenvolume; a passageway defined axially through said plug from said andthrough depression to and through said inner end of said plug; thedifference between said second and third given volumes beingsubstantially equivalent to the portion of said first given volume whichin normal expected use of said cannula is occupied by residualmedicament liquid upon conclusion of an incident of dispensing ofmedicament liquid through said well into said liquid path.